Brultech Electrical Power Monitoring for your Home

[murphy]

.... I have some Step up / down transformers here ,, How do I check them to insure that the phase shift is OK (Is smaller better [Less mass to charge ??) ??? 

The phase-shift of any transformer is not too far from 0 (or 180 if you change the wires, but that doesn't matter in this case).
Theoretically a larger / more heavy transformer should have a little less phase-shift because the core is more idling and (/or?) the coil has a lower inductance (?).

A real zero phase-shift you have, when you are reducing the voltage not by a transformer but by a potentiometer (no capaticance, no inductiv influence) Maybe this is energywasting, but two lamps in serie one for 220 V and one for 12 V (for the same current!) will work. But this should be an arrangement for the labs of BrulTec, when determining the poor some degrees of phaseshift of a transformer!

In the real world any transformer will work: even a phaseshift of +/-10° is not too important because the cosinus of this angle (which is the "Power-Factor") is rather near 1. And because we are speaking of energysavings: use any small transformer you have available. And avoid all the shipping. The necessary transformed power is sure under 1 W. Or needs the device more than 80 mA at 12 V? (If I'm wrong: BtechRep, please correct me !)

 

[jhimmel]

BtechRep,
Any ETA on the wired ethernet version? This would be the power monitoring solution I have been waiting for, but if it's too long I may settle on the ZigBee version since it is a decent solution as well.

I didn't see an answer to this question.
I am very interested in the Ethernet version as well. Any news?

Jim H.

 

[Btech]

BtechRep,

I have a 600 amp service. 3 x 200. Do you offer any configurations that would work with this?

Brian

We can use a setup consisting of six CTs on one ECM-1220.H. This would require one 200A Pkg and two Y-SPLIT-200 sets.

Paul

 

[Btech]

Originally posted by dBeau in the TED thread and moved to this one:

How does the software work as far as passing the data to the PC? the unit seems to store the data in real time so can you hook it up to a pc and dump out a months worth of data or does the PC need to be up 24-7 to get a full set of data?

I installed an ECM1220 a couple of months ago. It's a great device. They have some software for windows that allows both realtime readings as well as downloading of history. The device protocol is very simple to work with. It took me less than an hour to put together a python script that would run from my SuSE box and grab the realtime samples so I havnt used their software much and cant comment on it. Their protocol docs arent complete but they claim they are working on it. One of these days I'll write and bug them for an update on how to set the history sample period. But since I am constantly sampling I really dont need the feature. The sample rate is about once per second with a 1 joule (watt/sec) resolution from each of the two channels.

My biggest complaint is that they only have a usb interface. When plugged in, it appears as a serial port so programming is not a problem, it's just a bit limiting in that the device you connect it to needs to support usb and have a driver for the serial chipset. Anything I have with a 2.6 kernel or better has worked, and this includes my nslu2. I'd would have preferred ethernet or straight rs232 for more flexibility.

I'm glad you are enjoying your ECM-1220.H. FYI, we have a new firmware version

available on our site. This new version has a new packet format in addition to the

current ones. The new format offers greater flexibility and now accomodates net

metering for solar and wind systems. We hope to have more information on this available

shortly.

There are some possible alternatives to the USB only situation. One possibility would

be to use Digi's (digi.com) XBEE to RS-232 adaptor along with a zigbee equipped monitor

(we use digi ZNET2.5 zigbee modules)
http://www.digi.com/products/wireless/zigb...es2-adapter.jsp

For you hackers, you can easily interface ZNET2.5 module ($23) to a MAX3232 chip for

RS-232 communication. You can also apply a similar solution using an RS232 to ethernet

module saelig.com in conjunction with a the zigbee module for TCP/IP solution.

Our new boards can provide a TTL rs-232 signal directly from an internal header. We

currently do not populate this area of the board however anyone wishing this option

could let us know in advance. We will populate a limited number of boards during our

next production run for anyone interested.

BtechRep,

Any ETA on the wired ethernet version? This would be the power monitoring solution I have been waiting for, but if it's too long I may settle on the ZigBee version since it is a decent solution as well.

If you are interested in a direct to ethernet version, we now can add this feature to your unit. Please email me: support @brultech.com

Paul

 

[Btech]

Hi BTechRep,

I note on your site that it says the system can measure 220V 50Hz with special firmware. Will you release a version soon to those of us living in countries that have this type of electricity supply? I for one (amongst many others in NZ) would purchase immediately as there are no resellers of realtime power monitors and dataloggers that I can find in the Southern Hemisphere....

- if anyone knows of one please PM me!!!!

Macca,

We now have firmware for use on 220V/50Hz systems. We currently only have a limited number of european-style (two-pin) wall transformers.

Paul

 

[Btech]

.... I have some Step up / down transformers here ,, How do I check them to insure that the phase shift is OK (Is smaller better [Less mass to charge ??) ??? 

The phase-shift of any transformer is not too far from 0 (or 180 if you change the wires, but that doesn't matter in this case).
Theoretically a larger / more heavy transformer should have a little less phase-shift because the core is more idling and (/or?) the coil has a lower inductance (?).

A real zero phase-shift you have, when you are reducing the voltage not by a transformer but by a potentiometer (no capaticance, no inductiv influence) Maybe this is energywasting, but two lamps in serie one for 220 V and one for 12 V (for the same current!) will work. But this should be an arrangement for the labs of BrulTec, when determining the poor some degrees of phaseshift of a transformer!

In the real world any transformer will work: even a phaseshift of +/-10° is not too important because the cosinus of this angle (which is the "Power-Factor") is rather near 1. And because we are speaking of energysavings: use any small transformer you have available. And avoid all the shipping. The necessary transformed power is sure under 1 W. Or needs the device more than 80 mA at 12 V? (If I'm wrong: BtechRep, please correct me !)

Murphy,

I agree that a voltage divider is the ultimate for monitoring the line voltage as it will introduce 0 phase error. This is the method used for most electronic house meters and also used by the kilawatt and I suspect the TED. The problem with this method is that makes your circuit live and requires some other means of isolation between the user and any other connected device. We have elected to use the wall transformer as a potential transformer which provides line isolation and easy of installation (plug in nearby outlet).

As for the transformer phase shift, we strive to keep this low. I agree that a 10 degree phase error for resistive loads (PF=1) will only introduce a 1.5% error which may be acceptable for some, however, if you are monitoring a motorized load with a 0.766 power factor, a 10 degree phase error will cause an 11.5% error.


As for the cost of electricity in Germany, that is quite high. I was aware that gasoline was expensive in Europe but didn't realize electricity was so high. Regardless of energy prices and savings, Texas is a lovely state and nice place for a farm.

Paul